As of Friday afternoon, traffic was rolling in a third lane eastbound on the Richmond-San Rafael Bridge for the first time in 40 years.

“This is truly something we have all been waiting for,” said Marin Supervisor Damon Connolly at a morning event near the foot of the span. “Opening the third lane will bring real traffic relief that is badly needed.”

By late Friday afternoon, 3.5 hours after the lane opened, traffic was flowing smoothly southbound along Highway 101 at the I-580 connector, often jammed with traffic getting to the span. Highway 101 northbound to Sir Francis Drake Boulevard still had a slowdown as did the Bellam Boulevard offramp to the span, but both had traffic that was lighter than usual. On the bridge itself traffic was moving at the limit.

New signs on eastbound Highway 580 notify drivers that the third eastbound lane on Richmond-San Rafael Bridge is open. (Robert Tong/Marin Independent Journal)

“We will keep monitoring it in the coming weeks to see how the traffic flows,” said Dianne Steinhauser, executive director of the Transportation Authority of Marin, which helped push the project through.

The 5.5 mile bridge initially had three lanes when it opened in 1956, but when drought hit in 1977 a lane on the top deck was closed so a pipeline could be placed across the span to bring water to Marin. When the pipeline was removed in 1978, the top and lower deck lanes were converted to shoulders because of light traffic.

Over the past five years, traffic has increased about 15 percent on the Richmond-San Rafael Bridge as the economy has rebounded.

“With a healthy economy and strong job growth, traffic access to the bridge has steadily increased and the associated traffic backups have skyrocketed,” said Connolly, who also sits on the Metropolitan Transportation Commission and Transportation Authority of Marin.

As of Friday a changeable message sign now greets drivers as they approach the bridge on the Marin side, advising whether the lane can be used. It can hardly be missed — it’s of Las Vegas-sized proportions and brightness.

Over the lanes, suspended from the upper deck, are 20 signs drivers can see. A green arrow means the lane can be used, a red “X” means drivers need to stay out.

“On this bridge, the red ‘X’ is regulatory, meaning you can’t drive in the lane,” said California Highway Patrol spokesman Andrew Barclay.

The cost for being in the lane when it’s verboten is pricey: a $237 ticket and a point on the driving record. The lane is set off by a solid white line, but it’s legal for drivers to cross it when they are allowed in.

The third lane will be open to drivers from 2 p.m. to 7 p.m. daily. The third lane will be used by Caltrans for maintenance and as an emergency lane at other times.

The $53 million project involved putting signs up, striping the bridge, shoving back a retaining wall on the Contra Costa side and making improvements to the bridge approach on the Marin side.

“We know this will relieve commute aggravation for East Bay residents who commute to jobs in Napa, Sonoma, Marin and San Francisco,” said Amy Worth, mayor of Orinda and member of the Metropolitan Transportation Commission.

With the eastbound lane now available, eyes turn toward how best to use the westbound third lane on the top deck. It’s now closed, but initial plans had it pegged for a bike lane separated by the movable barrier, similar to the one used on the Golden Gate Bridge. But Connolly and others are agitating to allow cars to use the lane at peak commute times, while having bike access during other periods.

Last month, the Bay Area Toll Authority’s Oversight Committee OK’d spending $100,000 to study whether adding vehicles to the lane is feasible and what it would take to accomplish the work.

<p/> <p>A massive highway bridge collapsed over the Italian city of Genoa during a rainstorm Tuesday, causing concrete and cars to fall several stories onto buildings and killing at least 11 people, according to a state run news agency.